There are a lot of variables are you wanting to be a retailer?If so you need a 100% oxygen set up.Heat packs & cold packsInsulated shipping boxesplastic bagsAn account with Fedex (they require a test shipment)

You should check out the new breathable bags no Oxygen needed in the bags. Cuts down on cost as far as an O2 tank and shipping becomes cheaper due to smaller box being used. here is a link this is the only place that sells them for now.

I agree breather bags are a waste of money, people have been shipping fish for decades and never needed breather bags. I have shipped thousands of fish using oxygen in regular bags and never had any problems.

LOL...I agree with shipping fish in a bag with O2 have done over a thousand myself that way but since the breathable bags it has cut down on my cost and are not a waste of money they actually save money. They also save some of my customers money I can ship more fish for less money. I also know for a fact a fish will do better and can live longer in a breathable bag vs a bag with O2. But I guess like everything else it is just a matter of preference some believe hang on the back filters are best other believe in wet drys they both do the job of keeping the fish alive.